The MoMent (MOther MENTor) is an implementation research study that is evaluating the impact of structured vs routine peer support on PMTCT outcomes in Nigeria, focusing on two North-Central states, the Federal Capital Territory and Nasarawa. The intervention consists of a simple but detailed standardized training curriculum for MMs coupled with daily MM supervision by dedicated personnel as well as standardized, user-friendly tools for both MMs and their supervisors to use for service delivery. These trained MM, along with trained MM Supervisors, form the basis of the Mentor Mother Intervention package. The choice of rural areas served by Primary Healthcare Centers is due to the fact that PMTCT coverage and uptake is lowest in these areas; the study sites are located in hard-to-reach-areas where a significant number of PMTCT-eligible clientele live.